Effect of planting date and nitrogen level on grain yield of hybrid rice

An experiment was conducted to find out grain yield and nitrogen uptake by hybrid rice under different planting dates and N levels during 2007 and 2008. The hybrid rice planted on July 1 or July 15 had significantly higher grain yield and N uptake. Delayed planting between August 1 and August 16 significantly reduced the grain yield to the extent of 21.1% and 36.4%, respectively compared with planting of July 1. Number of effective tillers, grains panicle⁻¹, test weight, grain yield, N concentration and uptake by grain and straw increased significantly with increasing levels of N from 60 to 120kg ha⁻¹.